15. Warning Systems Flashcards
PSEU Light
- Also illuminates for overwing exit flight lock fails to disengage when commanded,
- Inhibited from Thrust Lever advance for T/O until 30s after landing
- For some aircrafts acts also with “Simple Fault” logic,
- In this case illuminates after landing, extinguishes after Parking Brake SET or both engines shutdown
MACH AIRSPEED AND STALL WARNING TEST Switches Inhibit
While airborne
Landing Gear Warning Cutout Switch
Cannot be silenced with Flaps > 10
Current Altitude Alert
- White box shows around current altitude display becomes bold,
- Between 900-300FT before reaching the selected altitude,
- The box turns amber and flashes for 300-900FT deviation from the selected altitude
BELOW G/S P-INHIBIT Light
If pushed below 1000FT RA, inhibits Ground Proximity GLIDESLOPE alert
GRD PROX INOP Light
- GPWS computer malfunction or power loss,
- Invalid signals received from: RA, ADIRU, ILS, IRS, FMC, SMYD computers or EFIS panel
TERR INHIBIT Switch
Inhibits Look-Ahead terrain alerts and terrain display
RUNWAY INOP Light
- RAAS failure,
- GPS position accuracy is inadequate,
- The airport is not in the GPWS database,
- The airport is not in the RAAS RWY database
Terrain Display Color Codes
- Dotted Green: 2000FT below to 500Ft (250FT with gear down) below the aircraft,
- Dotted Amber: 500Ft (250FT with gear down) below to 2000FT above the aircraft,
- Dotted Magenta: No terrain data available,
- Solid Red: Look-Ahead warning is active,
- Solid Amber: Look-Ahead caution is active,
- Solid Green: Highest elevation
Terrain Inhibit Near Airport
Within 200/400FT of nearest airport RWY elevation does not show
Predictive Windshear Auto Pop-up
- Even neither pilot has WXR display selected,
- In Expanded Modes and Center Map Mode,
- If TERRAIN selected, WXR replaces it
Sound Alerts
- Clacker for airspeed,
- Warning tone for A/P disengagement,
- Intermittent horn for Takeoff Config and Cabin Altitude,
- Steady Horn for Landing Gear positions,
- Warning Bell for Fire
Warning Light Colors
- RED: Requires immediate attention,
- AMBER: Requires timely attention,
- BLUE: System information
Importance of MASTER CAUTION or FIRE RESET
Resets the system for future warnings
MASTER CAUTION Associated Area
Outside the normal field of vision of the flight crew
Simple Fault
- Single fault in certain redundant systems,
- Does not illuminate MASTER CAUTION,
- Stored in the system and illuinate during Recall, extinguishes after RESET
MASTER CAUTION Lights and Recall
All 12 lights must be illuminated
MASTER CAUTION OVERHEAD Unusual Lights
- EQUIP COOLING-OFF,
- EMER EXIT LIGHTS-NOT ARMED
Takeoff Configuration Warning
- Trailing Edge Flaps not in the range of 1-25,
- Trailing Edge Flaps are in Skew or Asymmetry or have Uncommanded Motion,
- Leading Edge Devices not configured for takeoff or have Uncommanded Motion,
- SPEED BRAKE Lever not in the DOWN position,
- Spoiler Control Valve is open, providing pressure to Ground Spoiler Interlock Valve,
- Parking Brake is SET,
- Stabilizer Trim not set in the takeoff range
Landing Gear Horn Activation
Flaps Up to Flaps 10:
- Below 800FT, either Thrust Levers between IDLE and 20 degrees,
- OEI Thrust Lever < 34 degrees,
- Can be silenced until 200FT RA
Flaps 15 to 25:
- Either Thrust Lever < 20 degrees (or 34 for OEI),
- Cannot be silenced
Flaps greater than 25:
- Regardless of Thrust Lever position,
- Cannot be silenced
PSEU System Monitors
Proximity Switch Electronic Unit monitors:
- Takeoff Configuration Warnings,
- Landing Configurations Warnings,
- Landing Gear,
- Air/Ground sensing
Stall Warning Purpose
- Natural Stall Warning (buffet) usually occurs at a speed prior to stall,
- In some configurations the margin between stall and natural stall warning is less than desired,
- Therefore an artificial Stall Warning Device, a Stick Shaker is used to provide the required warning
SMYD and Sources
Stall Management and Yaw Damper computers takes data from:
- Alpha Vane AoA outputs,
- ADIRU outputs,
- Anti-ice controls,
- Wing configurations,
- Air/Ground sensing,
- Thrust
SMYD Outputs
- Stick Shaker and Pitch Limit Indicator,
- Airspeed displays,
- GPWS Windshear detection and alert
Altitude Alert Inhibit
- Flaps 25 or greater or,
- G/S captured
GPWS Inputs
- Radio Altitude,
- Barometric Altitude,
- Airspeed,
- Glideslope deviation,
- Airplane configuration
GPWS Alerts
Radio Altitude based alerts:
- Excessive Descent Rate,
- Excessive Terrain Closure Rate,
- Altitude Loss after Takeoff or Go-around,
- Unsafe Terrain Clearance when not in the landing configuration,
- Excessive deviation below ILS/GLS Glideslope or the FMC generated flight path angle
Look-Ahead Terrain Alerts:
- In addition to GPWS, EGPWS monitors terrain proximity,
- Using an internal worldwide terrain database
Warning Authority
- Actual Windshear warning,
- GPWS,
- Predictive Windshear,
- TCAS
Look-Ahead Terrain Alerts
- EGPWS contains detailed terrain data near major airports,
- And data in lesser detail for areas between airports,
- Terrain within 200FT of aircraft barometric altitude shows on the ND,
- Generated from database in the EGPWS computer and correlated to GPS position,
- Alerts based on aircraft: Position, Barometric Altitude, Vertical Flight Path and Ground Speed
GPWS Warnings/Cautions
- TERRAIN TERRAIN/OBSTACLE OBSTACLE, PULL UP: 20-30s to projected impact,
- CAUTION TERRAIN/OBSTACLE: 40-60s to projected impact,
- TOO LOW TERRAIN: Descent below unsafe altitude while too far from database airports, may follow DON’T SINK,
- TERRAIN: Excessive terrain closure rate,
- PULL UP: Follows SINK RATE and changes to TERRAIN,
- DON’T SINK: Excessive altitude loss after Takeoff or Go-around,
- SINK RATE: Excessive descent rate,
- TOO LOW, FLAPS/GEAR: Unsafe terrain clearance at low speed without correct configuration
RAAS Operation Requirements
- Terrain and airport runway database is in the GPWS computer,
- Aircraft approaching an airport in the RAAS database,
- GPS and other required signals are available and accuracy meets minimum requirements,
RAAS AAL Algorithm
- Numerically subtracts the landing runway touchdown zone elevation in the GPWS,
- From the pressure altitude of the aircraft
“APPROACHING XX” RAAS Advisory
Inflight:
- Between 750-300FT AAL and,
- Within 3NM of the approach end of the RWY and,
- Track within 20 degrees of the RWY HDG and,
- Laterally within 200FT of the RWY centerline + RWY width
On the ground:
- Groundspeed < 40KT and,
- Within specific distance from the RWY
“APPROACHING SHORT XX” RAAS Advisory
- Same as normal call except for RWY length < 1900m,
- And shown in amber
“ON XX” RAAS Advisory
- On RWY and,
- Heading within 20 degrees of RWY heading,
- Heard twice when aircraft along distance change is < 100FT within 180s
Unstable Approach RAAS Cautions
- “FLAPS FLAPS”,
- “TOO HIGH, TOO HIGH”,
- “TOO FAST, TOO FAST”,
- “UNSTABLE, UNSTABLE”,
- “LONG LANDING, LONG LANDING”,
- “CAUTION TAXIWAY, CAUTION TAXIWAY”
GPWS Windshear Alert
- Two tone siren followed by “WINDSHEAR X 3”,
- Red WINDSHEAR on both Attitude Indicators,
- Begins at rotation an enabled below 1500FT RA
Predictive Windshear Alerts
- All enabled below 1200FT RA,
-“WINDSHEAR AHEAD”: During Takeoff,
-“GO AROUND, WINDSHEAR AHEAD”: Within 1.5NM ahead of aircraft during approach,
-“MONITOR RADAR DISPLAY”: Within 3NM during approach and takeoff, - Except MONITOR, Red WINDSHEAR shown on both Attitude Indicators and NDs,
- For MONITOR RADAR DISPLAY: Windshear symbol and amber WINDSHEAR shown on ND
Predictive Windshear Automatic Scan
- Thrust Levers set for takeoff (even engine is off and IRSs not aligned for some aircrafts) or,
- Inflight below 2300FT (1800FT for some aircraft) RA,
- Alerts available approximately 12s after scan begins
Predictive Windshear Scan Area
- 25 degrees left and right,
- 3NM long,
- Warning zone: 0.5NM beam width, Up to 3NM length on the ground and 1.5NM inflight
Predictive Windshear Inhibits
- New Cautions inhibited between 80KT and 400FT RA,
- New Warnings inhibited between 100KT and 50FT RA
GPWS RA Callouts
- For some aircraft 500 and 1000 callouts are barometric based,
- Triggered by the difference between barometric altitude and landing field elevation
Smart 500 RA Callout
- Used during non-ILS or non-GLS approach,
- Also during ILS approach with excessive deviation (2 dots of LOC or G/S),
- Used when G/S cancel is selected,
- Used also when Backcourse Approach is detected
DH/MDA Callout Source
CPTs Minimums selector
TCAS General
- Traffic Alert and Collision Avoidance System,
- No protection against the aircrafts which do not have operating transponders,
- Identifies 3D airspace around the aircraft,
- Dimensions based upon closure rate with the conflicting traffic
- Independent of Ground-based ATC
TCAS Advisories
- TA: “TRAFFIC TRAFFIC”, 40s to closest approach point, red square,
- RA: 25s to closest approach point, amber circle,
- Proximate traffic: Within 6NM and 1200FT, solid white diamond,
- Other traffic: Beyond proximate criteria, empty white diamond
TCAS Inhibits
-“INCREASE DESCENT”: Below 1500FT RA,
-“DESCEND”: Below 1100FT RA,
- RAs inhibited below 1000FT RA, changes to TA ONLY mode,
- All voice advisories inhibited below 500FT RA
